1. Field of the Invention
The invention relates in general to electrical transformers, and more specifically, to new and improved methods of constructing transformers which include an uncut, unjointed magnetic core.
2. Description of the Prior Art
The core losses in the electrical transformers used by electric utility companies represents a significant loss of generated energy, even though transformers are highly efficient. With the increasing value of energy, ways of reducing these losses are constantly being sought. The use of amorphous metal in the magnetic cores of distribution and power transformers appears to be attractive, because, at equivalent inductions, the core losses of electrical grade amorphous metals are only 25% to 35% of the losses of conventional grain-oriented electrical steels.
Amorphous metals, however, in addition to their higher initial cost than conventional electrical steels, also pose many manufacturing problems not associated with conventional electrical steels. For example, amorphous metal is very thin, being only about 1 to 11/2mils thick, and it is very brittle, especially after anneal. Thus, with the wound magnetic cores conventionally used with distribution transformers, the core joint becomes a problem, making the use of a jointless magnetic core very attractive. This means that the primary and secondary windings of the transformer must be wound about the magnetic core. Amorphous metal is also very stress sensitive. Any pressure on the magnetic core, or change in its configuration after annealing, will increase its losses.
Thus, it would be desirable to provide new and improved methods for economically manufacturing an electrical transformer having an unjointed, pressure sensitive magnetic core.